diff --git a/app/controllers/api/functions.php b/app/controllers/api/functions.php
index a32615161..88ad27521 100644
--- a/app/controllers/api/functions.php
+++ b/app/controllers/api/functions.php
@@ -1311,7 +1311,7 @@ App::post('/v1/functions/:functionId/variables')
     ->label('sdk.response.type', Response::CONTENT_TYPE_JSON)
     ->label('sdk.response.model', Response::MODEL_VARIABLE)
     ->param('functionId', null, new UID(), 'Function unique ID.', false)
-    ->param('key', null, new Text(255), 'Variable key. Max length: 255 chars.', false)
+    ->param('key', null, new Text(Database::LENGTH_KEY), 'Variable key. Max length: ' . Database::LENGTH_KEY  . ' chars.', false)
     ->param('value', null, new Text(16384), 'Variable value. Max length: 16384 chars.', false)
     ->inject('response')
     ->inject('dbForProject')